1998 DODGE RAM 1500 air

(13) Install the cooling fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(14) Connect battery negative cables.
(15) Start engine and check for oil leaks.
INTAKE MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the charge air cooler outlet tube from
the air inlet housing (Fig. 118).
(3) Remove the engine oil dipstick tube mounting
bolt (Fig. 118).
(4) Remove dipstick support at fuel filter housing.
Position dipstick tube to the side.
(5) Disconnect the air grid heater power cables at
the cable mounting studs.
(6) Disconnect the ground strap at the intake
cover.
(7) Remove the engine wiring harness connections
at the air inlet housing elbow.
(8) Remove the four (4) air inlet housing mounting
bolts and remove the housing from top of the heater
elements.
(9) Remove the intake air grid heater from the
manifold (Fig. 119).
(10) Remove the high pressure fuel lines and fuel
rail (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
FUEL LINES - REMOVAL).
(11) Remove APPS bracket from cylinder head to
gain access to front intake manifold cover bolts.
(12) Disconnect manifold air temperature/pressure
sensor connector.
(13) Remove the remaining intake manifold cover-
to-cylinder head bolts.
(14) Remove the intake manifold cover and gasket.
Keep the gasket material and any other material out
of the air intake.
(15) Clean the intake manifold cover and cylinder
head sealing surface.
CLEANING
Clean manifold in solvent and blow dry with com-
pressed air.
Clean cylinder block gasket surfaces using a suit-
able solvent.
The plenum pan rail must be clean and dry (free of
all foreign material).
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straightedge.
Fig. 118 Charge Air Cooler Air Tube
1 - FRONT WIRING CLIP
2 - GROUND CABLE
3 - TUBE BOLT
4 - ENGINE OIL DIPSTICK TUBE
5 - CLAMPS
6 - AIR TUBE (INT. MAN.-TO-INTERCOOLER)
7 - RUBBER HOSE
8 - AIR INTAKE HOUSING
9 - CABLE BRACKET HOUSING
Fig. 119 Intake Air Grid Heater
1 - INTAKE AIR GRID HEATER
2 - GASKET
DRENGINE 5.9L DIESEL 9 - 297
OIL PUMP (Continued)

INSTALLATION
(1) Using a new gasket, install the intake manifold
cover.
(2) Install the cover-to-cylinder head bolts that do
not hold down the fuel rail. Tighten the bolts to 24
N´m (18 ft. lbs.) torque.
(3) Install the high pressure rail and fuel lines
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
FUEL LINES - INSTALLATION).
(4) Using two (2) new gaskets, install the intake
air grid heater and air inlet housing. Position the
ground cable and install and tighten the bolts to 24
N´m (18 ft. lbs.) torque.
(5) Connect the manifold air temperature/pressure
sensor connector.
(6) Install and tighten the air intake heater power
supply nuts to 14 N´m (120 in. lbs.) torque.
(7) Install the APPS bracket. Torque fasteners to
43 N´m (32ft lbs.) torque.
(8) Install oil dipstick tube support at fuel filter
housing.
(9) Install the engine oil dipstick tube and mount-
ing bolt.
(10) Position the charge air cooler outlet tube onto
the air inlet housing. Tighten the clamps to 11 N´m
(100 in. lbs.) torque.
(11) Attach the engine wire harness to the air inlet
housing at two locations.
(12) Prime the fuel system. Refer to the fuel prim-
ing procedure in Group 14, Fuel System.
(13) Connect the battery negative cables.
EXHAUST MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Disconnect the exhaust pipe from the turbo-
charger elbow.
(4) Disconnect oil drain tube from turbocharger.
(5) Lower vehicle.
(6) Disconnect the turbocharger air inlet hose.
(7) Remove air cleaner assembly.
(8) Disconnect the turbocharger oil supply line.
(9) Disconnect the charge air cooler inlet pipe from
the turbocharger.
(10) Remove the turbocharger and gasket from the
exhaust manifold.
(11) Remove the cab heater return pipe nuts from
the exhaust manifold stud. Position the tube out of
the way.
(12) Remove heat shield.
(13) Remove exhaust manifold bolt lockplates.
(14) Remove the exhaust manifold-to-cylinder head
bolts and spacers (Fig. 120).(15) Remove the exhaust manifold and gaskets
(Fig. 120).
CLEANING
Clean the cylinder head and exhaust manifold seal-
ing surfaces with a suitable scraper. Use a Scotch-
BriteŸ pad or equivalent.
INSPECTION
Inspect the exhaust manifold for cracks. Measure
the exhaust manifold for flatness. Place a ruler over
all of the exhaust ports and insert a feeler gauge
between the port flange and the ruler. Maximum
deviation from flat is 0.20 mm (.008 inch).
INSTALLATION
(1) Using new gaskets, install the exhaust mani-
fold and gaskets. Install the bolts and spacers and
tighten the bolts in the sequence shown in to 43 N´m
(32 ft. lbs.) torque.
(2) Retorque the four center bolts.
Fig. 120 Exhaust Manifold and Gaskets
1 - RETAINING STRAP
2 - BOLT (7)
3 - SPACER
4 - MANIFOLD, EXHAUST
5 - GASKET
6 - BOLT (5)
9 - 298 ENGINE 5.9L DIESELDR
INTAKE MANIFOLD (Continued)

(3) Install heat shield and torque nuts to 15 Nm
(11 ft. lbs.).
(4) Install cab heater tube.
(5) Install exhaust manifold bolt retention straps.
(6) Install the cab heater return hose to the man-
ifold bolt stud. Tighten the nut to 24 N´m (18 ft. lbs.)
torque.
(7) Install the turbocharger and a new gasket.
Apply anti-seize to the studs and then tighten the
turbocharger mounting nuts to 43 N´m (32 ft. lbs.)
torque.
(8)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting on the turbo. Rotate the turbocharger impeller
by hand to distrubute the oil thoroughly.
(9) Install and tighten the oil supply line fitting
nut to 24 N´m (18 ft. lbs.) torque.
(10) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (100 in. lbs.) torque.
(11) Position the air inlet hose to the turbocharger.
Tighten the clamp to 11 N´m (100 in. lbs.) torque.
(12) Raise vehicle on hoist.
(13) Install the oil drain tube and a new gasket to
the turbocharger. Tighten the drain tube bolts to 24
N´m (18 ft. lbs.) torque.
(14) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 11 N´m (100 ft. lbs.) torque.
(15) Lower the vehicle.
(16) Connect the battery negative cables.
(17) Start the engine to check for leaks.
VALVE TIMING
STANDARD PROCEDURE - TIMING
VERIFICATION
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Remove fuel injector from cylinder number
1(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
FUEL INJECTOR - REMOVAL).
(3) Using Special Tool 7471B rotate the engine
until the TDC mark on the damper is at 12 o'clock.
(4) Using a 8 in.x 1/4 in. dowel rod inserted into
cylinder number 1, rock the crankshaft back and
forth to verify piston number 1 is at TDC.
(5) With cylinder number still at TDC, inspect the
keyway on the crankshaft gear for proper alignment
(12 o'clock position).
(6) If the keyway is not at 12 o'clock position
replace the crankshaft gear assembly.
(7) If the keyway is at 12 o'clock position, remove
front gear cover and verify timing mark alignmentbetween the camshaft gear and crankshaft gear, if
not aligned inspect keyway on camshaft gear.
(8) Inspect keyway on camshaft gear for proper
alignment with the key in the camshaft, if alignment
is off replace the camshaft/gear assembly.
(9) If timing marks alignment is off and no dam-
age is found at either the crankshaft or camshaft
gear keyways, realign timing marks as necessary.
GEAR HOUSING
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Partially drain engine coolant into container
suitable for re-use (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(4) Lower vehicle.
(5) Remove radiator upper hose.
(6) Disconnect coolant recovery bottle hose from
radiator filler neck and lift bottle off of fan shroud.
(7) Disconnect windshield washer pump supply
hose and electrical connections and lift washer bottle
off of fan shroud.
(8) Remove lower fan shroud fasteners. Disconnect
fan drive wire harness.
(9) Remove the upper fan shroud-to-radiator
mounting bolts.
(10) Remove viscous fan/drive assembly (Refer to 7
- COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(11) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(12) Remove the cooling fan support/hub from the
front of the engine.
(13) Raise the vehicle on hoist.
(14) Remove the crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and speed indicator ring.
(15) Lower the vehicle.
(16) Remove the power steering pump.
(17) Remove the accessory drive belt tensioner.
(18) Remove the gear cover-to-housing bolts and
gently pry the cover away from the housing, taking
care not to mar the gasket surfaces.
(19) Remove the fuel injection pump (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL INJEC-
TION PUMP - REMOVAL).
(20) Disconnect the camshaft position sensor con-
nector.
(21) Disconnect and remove engine speed sensor.
(22) Remove the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - REMOVAL).
(23) Remove the six front oil pan fasteners.
DRENGINE 5.9L DIESEL 9 - 299
EXHAUST MANIFOLD (Continued)

EXHAUST SYSTEM
TABLE OF CONTENTS
page page
EXHAUST SYSTEM
DESCRIPTION
DESCRIPTION........................1
DESCRIPTION - 5.9L DIESEL.............3
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - GAS ENGINE . . . 4
DIAGNOSIS AND TESTING - DIESEL
ENGINE..............................5
SPECIFICATIONS - TORQUE...............5
SPECIAL TOOLS........................6
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER.....6
OPERATION............................6
REMOVAL
REMOVAL............................6
REMOVAL............................6
INSPECTION...........................6
INSTALLATION
INSTALLATION........................6
INSTALLATION........................7
EXHAUST PIPE
REMOVAL - 3.7L/4.7L/5.7L.................7
INSPECTION...........................7
INSTALLATION - 3.7L/4.7L/5.7L..............7
EXHAUST PIPE
REMOVAL - DIESEL......................7
INSPECTION...........................8
INSTALLATION - DIESEL..................8
HEAT SHIELDS
DESCRIPTION..........................8
REMOVAL.............................8
INSTALLATION..........................8
MUFFLER
REMOVAL.............................9INSTALLATION..........................9
MUFFLER - 5.9L DIESEL
REMOVAL.............................10
INSTALLATION.........................10
TAILPIPE - 5.9L DIESEL
REMOVAL.............................10
INSPECTION..........................10
INSTALLATION.........................11
TAILPIPE
REMOVAL.............................11
INSPECTION..........................11
INSTALLATION.........................11
TURBOCHARGER SYSTEM
DIAGNOSIS AND TESTING -
TURBOCHARGER BOOST PRESSURE.....11
TURBOCHARGER
DESCRIPTION.........................12
OPERATION...........................13
REMOVAL.............................14
CLEANING............................15
INSPECTION..........................15
INSTALLATION.........................15
CHARGE AIR COOLER AND PLUMBING
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS..............16
REMOVAL.............................17
CLEANING............................17
INSPECTION..........................17
INSTALLATION.........................17
EXHAUST SYSTEM
DESCRIPTION
DESCRIPTION
CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.The federal gasoline engine exhaust system con-
sists of engine exhaust manifolds, exhaust pipes, cat-
alytic converter(s), extension pipe (if needed),
exhaust heat shields, muffler and exhaust tailpipe
(Fig. 1), (Fig. 2), (Fig. 3)
The California emission vehicles exhaust system
also contains the above components as well as mini
catalytic converters added to the exhaust pipe.
The exhaust system must be properly aligned to
prevent stress, leakage and body contact. Minimum
clearance between any exhaust component and the
body or frame is 25.4 mm (1.0 in.). If the system con-
tacts any body panel, it may amplify objectionable
noises from the engine or body.
DREXHAUST SYSTEM 11 - 1

DIAGNOSIS AND TESTING - DIESEL ENGINE
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts at leaking
joints.
2. Rusted or blown out muffler. 2. Replace muffler. Inspect exhaust
system.
3. Broken or rusted out exhaust
pipe.3. Replace exhaust pipe.
4. Exhaust pipe leaking at manifold
flange.4. Tighten/replace flange attaching
nuts/bolts.
5. Exhaust manifold cracked or
broken.5. Replace exhaust manifold.
6. Leak between exhaust manifold
and cylinder head.6. Tighten exhaust manifold to
cylinder head bolts. Replace gasket
if necessary.
7. Turbocharger mounting flange
cracked.7. Remove turbocharger and
inspect. (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER -
REMOVAL).
8. Restriction in exhaust system. 8. Remove restriction, if possible.
Replace restricted part if necessary.
SPECIFICATIONS - TORQUE
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Bolt-Adjusting Strap 23 - 200
Nuts-Air Heater Power
Supply14 - 124
Bolts-Air Inlet Housing 24 18 -
Nuts-Cab Heater Supply/
Return Line24 18 -
Nuts-Exhaust Clamp 54.3 40 -
Bolts-Exhaust Manifold to
Cylinder Head-(Diesel
Engine)43 32 -
Bolts-Exhaust Manifold to
Cylinder Head-(5.9L)31 23 -
Bolts-Exhaust Manifold to
Cylinder Head-(8.0L)22 - 195
Bolts-Exhaust Pipe to
Manifold31 23 -
Bolts-Generator Mounting 41 30 -
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Bolts-Charge Air Cooler
Mounting2-17
Nuts-Charge Air Cooler Duct 11 - 95
Bolt-Generator to Block-
Diesel24 18 -
Nuts and Bolts-Heat Shield 11 - 95
Turbocharger flange studs 24 18 -
Nuts-Turbocharger Mounting 43 32 -
Bolts-Turbocharger Oil Drain
Tube24 18 -
Fitting-Turbocharger Oil
Supply Line24 18 -
Nut-Turbocharger V-Band
Clamp5.6 - 70
Turbocharger Oil Supply
fitting (at Turbocharger)36 27 -
Turbocharger Oil Supply
fitting (at lube filter head)24 18 -
Turbocharger Drain Hose
Clamps8-71
DREXHAUST SYSTEM 11 - 5
EXHAUST SYSTEM (Continued)

(1) Position the catalytic converter onto the
exhaust pipe flange connection. Tighten the nuts to
28 N´m (250 in. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install the exhaust clamp at the muffler and
catalytic converter connection. Tighten the clamp
nuts to 54.2 N´m (40 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(7) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Install the exhaust pipe onto exhaust mani-
folds, tighten 31 N´m (23 ft. lbs.).
(3) Tighten all clamp nuts to 52.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(6) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
EXHAUST PIPE
REMOVAL - 3.7L/4.7L/5.7L
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove exhaust pipe to manifold bolts, retain-
ers and nuts.
(4) Remove the clamp nuts.
(5) Remove the exhaust pipe (Fig. 4).
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION - 3.7L/4.7L/5.7L
(1) Position the exhaust pipe for proper clearance
with the frame and underbody parts. A minimum
clearance of 25.4 mm (1.0 in.) is required.
(2) Position the exhaust pipe to manifold. Install
the bolts, retainers and nuts. Tighten the nuts to 31
N´m (23 ft. lbs.) torque.
(3) Tighten the clamp nuts to 54.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
EXHAUST PIPE
REMOVAL - DIESEL
(1) Disconnect the battery negative cables.
(2) Raise and support the vehicle on a hoist.
(3) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(4) Remove the exhaust pipe-to-extension pipe
clamp. Separate the exhaust pipe and extension pipe.
(5) Remove the exhaust pipe-to-turbocharger elbow
clamp (Fig. 5).
(6) Remove the exhaust pipe from the transmis-
sion support (Fig. 5).
Fig. 4 Exhaust Pipe to Manifold Connection -
Typical
1 - BOLT
2 - RETAINER
3 - EXHAUST MANIFOLD
4 - NUT
5 - EXHAUST PIPE
DREXHAUST SYSTEM 11 - 7
CATALYTIC CONVERTER (Continued)

INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION - DIESEL
(1) Install the exhaust pipe into the transmission
support and onto the turbocharger flange.
(2) Install the exhaust pipe-to-turbocharger elbow
clamp and tighten to 11 N´m (100 in. lbs.) torque.
(3) Install the extension pipe and clamp to the
exhaust pipe using a new clamp and tighten the
clamp nuts to 54.2 N´m (40 ft. lbs.) torque.
(4) Lower the vehicle.
(5) Connect the battery negative cables.
(6) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(7) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
HEAT SHIELDS
DESCRIPTION
There are two types of heat shields used. One is
stamped steel the other is molded foil sheets. The
shields attach to the vehicle around the exhaust sys-
tem to prevent heat from the exhaust system from
entering the passenger area and other areas where
the heat can cause damage to other components.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the nuts or bolts holding the exhaust
heat shield to the floor pan (Fig. 6) (Fig. 7) (Fig. 8),
crossmember or bracket.
(3) Slide the shield out around the exhaust system.
INSTALLATION
(1) Position the exhaust heat shield to the floor
pan, crossmember or bracket and install the nuts or
bolts.
(2) Tighten the nuts and bolts 11 N´m (100 in.
lbs.).
(3) Lower the vehicle.
Fig. 5 Exhaust Pipe
1 - Clamp
2 - Support
3 - EXHAUST PIPE
Fig. 6 HEAT SHIELDS - RH - REG CAB
1 - HEAT SHIELD
2 - FASTENER
3 - NUT
4 - HEAT SHIELD
11 - 8 EXHAUST SYSTEMDR
EXHAUST PIPE (Continued)

MUFFLER
REMOVAL
(1) Raise and support the vehicle.
(2) Saturate the clamp nuts with heat valve lubri-
cant. Allow 5 minutes for penetration.
(3) Disconnect the muffler hangers (Fig. 9).
(4) Remove clamps and nuts.
(5) Remove the muffler.
INSTALLATION
(1) Assemble muffler and clamps loosely to permit
proper alignment of all parts.
(2) Connect the muffler hangers.
(3) Tighten the clamp nuts to 54.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(6) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
Fig. 7 HEAT SHIELDS - RH - QUAD CAB
1 - HEAT SHIELD
2 - FASTENER
3 - NUT
4 - HEAT SHIELD
Fig. 8 HEAT SHIELD LH
1 - HEAT SHIELD
2 - NUT
Fig. 9 MUFFLER
1 - INSULATOR
2 - INSULATOR
3 - MUFFLER
4 - INSULATOR
DREXHAUST SYSTEM 11 - 9
HEAT SHIELDS (Continued)